Started using these rules recently, and since I have no player Navigators I didn't have to wade through these with someone else there. A few issues have come up, based almost entirely on Stage 5:

1) Doesn't the Voyage Duration chart (Table 2-4, pg 30) seem way too punitive? Miss the Nav check by 1 point, bam, double travel time.

2) The Accuracy of Re-Entry rules are way out of whack. Since there seems to be no opportunity for adjustment of steerage throughout the entire trip, the only way to finish on target is beat the Nav (Warp) test by between 1 and 9 points, since any failure and even a single Degree of Success puts you at least Slightly Off Course. If you crush the Nav Warp test (not terrible difficult given the plethora of bonuses you can get) and max out at 3 DoS, you are Severly Off Course land, putting you at risk of a serious time shift not to mention being potentially weeks off course, which would require yet more warp travel fun, all because your Navigator was too good at his job.

3) On Target mentions at the end that "the number of days that has elapsed in reality is equal to the actual duration of passage". Nevermind that this directly contradicts several references in the main book to the WarpTime = RealTime x12 rule, there are no similar time passage comments for Slightly or Severly Off Course.

4) The Plying The Warp Without A Navigator , if followed, would make Navigatorless "hops" by smaller vessels basically pointless, as the best you could hope for is landing the right sector and a 50% chance of either never returning or moving several years forward or backward in time.

5) In Lure Of The Expanse, there is a mention of dropping in and out of warp occasionally to get your barings. This isn't brought up anywhere else in any of the books that I can find. Is this a fluke with LotE or am I missing something there.

I'm cool with making warp travel a more story-based and less skill-test focused experience, and it's a good thing that I don't have any Navigator PCs, so I can abstract a lot of this, but this seems unusually slapdash, even for RT.

I don't really know what to tell you, apart from that I had the a similar experience after I bought the book, which is why I sent it back. (and I have never done this with any rpg book up until now).

But I remember that I felt that the rules were inconsistent with much of what was written before (no mention of calculated jumps, apart that without a navigator you are DOOMED!, no "on established, safe routes, NOTHING might happen) .

Also Warp Hallucinations alone (which happen everytime) had such severe consequences that you would probably lose half your crew on any longer voyage.

Apart from that I really didn't like the "new"(?)feel of navigators. I thought they were just people who could see and navigate the warp, without going mad, now they all had lots of weird rituals (some of which sounded pretty heretical) and would use their mind to protect the whole ship and crew from psychic incursions of the warp (I thought gellar fields did that?) . Also Astropaths are apparently so powerful now, that they can create Void Shield level telekinetic barriers around whole starships and influence gunners on enemy ships ten thousands of kilometers away with telepathy. I mean, sure, that's a cool thing to do for PCs, but isn't that completely above beyond their powers? If you can protect a whole starship from a Lance weapon, why can't you make yourself invulnerabe with a telekinetic shield?

Ok, I'm sorry, that this isn't really helpful at all, but I was really disappointed by the warp travel rules. The rest of the book is probably fine for NPCs and the awakened psyker seemed really cool, but that's not what I wanted. This is exactly like when I bought Battlefleet Koronus for the Ground Combat Rules (which are completely broken) (btw. the BC Tome of Blood seems to have useable mass combat rules)

My first impression was similar to yours, but after re-reading the entire chapter I'm thinking that we're just reading it wrong. Admittedly, it is clumsily written. Some of the assumptions we make due to the original warp travel rules from the core book further complicate this, so just try to forget what was written there (except for the 12x real time vs warp travel time passage, which I'm going to keep).

Simplified, here's what happens during a warp voyage:

1) The GM determines the actual time the journey will take.

2) The navigator tries to determine the same number and the risks involved in the journey. He may be wrong about either.

3) The ship translates into the warp.

4) The navigator locates the Astronomican.

5) The navigator steers the ship. His skill at this will determine the actual duration of the voyage. Now this is the important bit and the one I think you're reading wrong. The result from this roll changes both the GM's actual time estimate AND the navigator's estimate by the same factor. For example, if the GM determined that the trip would take 10 days and the navigator determined 20, but the result of the steering roll doubles the length of the voyage, the GM's new value is 20 and the navigator's is 40. The important part is that this knowledge is available to the navigator immediately. Once he starts steering the vessel he becomes aware that his original estimate was wrong and may inform the captain about this.

6) Potential warp encounters.

7) The ship leaves the warp. Once again, this is a part I think is being read wrong. To see if the ship is off course you compare the GM's duration with the navigator's duration. Nothing else is considered. Since both these values were adjusted by the results from table 2-4, things are more predictable than you might think. If the navigator correctly estimated the length of the journey in step 2 (my steps, not the book's), the GM's estimate and the navigator's will be the same regardless of the results from table 2-4, which means the ship arrives precisely on the target. If the navigator's original estimate was wrong however, the result from 2-4 can have an effect. To continue with my example from above, the difference between the GM's (adjusted) value of 20 vs the navigator's (adjusted) value of 40 means that the ship arrives in half the time the navigator expected (ironically in the time he originally estimated), which means the ship is slightly off course.

What this means is that an unskilled navigator will often give wrong estimates, journeys will tend to take longer, and translating back into realspace will be inaccurate. A skilled navigator will often give correct estimates that end up being wrong in the end because he ends up being able to steer the vessel better than expected, but this will have no adverse effects as long as the original estimate is correctly made. Crushing the navigator roll, to use the phrasing in the original post, has no negative consequence with a correct estimate.

Thematically I'd say that the skilled navigator is capable of taking greater risks with confidence, bringing the ship faster to its destination. This speed comes at a price, since mistakes are more dangerous. The overall effect should be that warp travel is unpredictable and dangerous, but having a skilled navigator on board the ship will let you get to your goal faster than the competition.

One sentence in the Accuracy of Re-entry section on page 34 says: "If the ship exited the Warp early for any reason, it is always severely Off-Course." Make sure you don't misread this sentence! It doesn't say that journeys shorter than the original estimate are always severely off-course. It refers to those unusual situations which force you to leave the warp before the navigator says the journey is complete. It's only natural that such re-entries are nowhere near where you intended to be.

Plying the warp without a navigator does indeed seem very, very dangerous with this system, but keep in mind that these rules are written for journeys through the Koronus Expanse, a notoriously unstable area of space filled with warp storms and far from the Astronomican. When traveling through "friendlier" areas such as the Calixis sector, I'd probably reduce the modifier to the final translation roll dramatically.

Archelaos, you mention warp hallucinations and that they happen every time. I don't see this in the rules, and I don't see how this would kill off your crew. These hallucinations only affect inexperienced player characters and important crew NPCs (which in my case would be one or two NPCs at most). The rest of the crew can be handwaved away and handled only through the Omens mechanic. The section on hallucinations even says that experienced warp travellers are less and less likely to be affected. My overall impression is that these hallucinations will mostly be a minor problem that will affect player characters once in a while, and they are likely to go away early in the journey anyway. If you're seeing something here that I'm not seeing, feel free to elaborate.

About step 5 in my explanation above, I want to make it clear that the navigator becomes aware of changes in the length of the journey at that point, but he still doesn't get to know the GM's estimate. I realized after posting that this paragraph could be unclear.

Wow, I completely missed the second paragraph under Navigation on page 30. Thanks for setting me straight. This makes a lot more sense, although I still feel the chart is overly punative. I also think there should be a chance for tuning your estimate as you go (maybe on an All's Well result?). Anyway, thanks, kind sir/madam.

I like to look at it as the first estimate roll being the point where the navigator calculates the end point of the journey and tries to figure out how long it would take to get there. He may be aware that he's so good (or so bad) that his estimate in all likelyhood must be updated once the ship translates, but it is so reliant on the conditions inside the warp that there's no way to tell before they do. Also, once they translate the navigator is no longer able to change the target he came up with in the first roll. No matter how calm the warp is, he still only has that result to go on.

Keep in mind that some events can update the journey's duration while you're in the warp. This doesn't change the calculated end point. If an event tells you to increase the length of the journey with 4 days, you need to update both the GM's estimate and the navigator's. Even if they get delayed or sidetracker, the navigator still knows where they need to go (or at least where he calculated that they need to go, which isn't necessarily accurate).

Yes, the first roll is punitive, which goes to show just how important a good map is if the navigator isn't extremely talented. A detailed map created by that navigator provides a +30 bonus, which is very significant. Also remember that even a failed roll has a 1/5 chance of giving you the correct results, even if the navigator reached it through all the wrong conclusions.